This invention relates generally to the field of ferrules used to join to hoses made of compressible, flexible material to metal tubes, pipes or stems, and more particularly to replacement ferrules which can be attached to such tubes which are already formed with single or double beads or shoulders to lock a ferrule onto the tube, and a method of attaching such replacement ferrules to such tubes.
It is necessary in many high pressure conduits to join a flexible hose made of high-strength yet somewhat compressible material, typically a composite of polymers, rubbers and reinforcing material to a metal tube, pipe or stems. One common method and apparatus for accomplishing this is to provide a sleeve ferrule consisting of an annular sleeve with one completely open end and one partially closed end, the partially closed end having a wall perpendicular to the longitudinal axis and a circular aperture sized to match the outer diameter of the metal tube to which it is to be connected. The sleeve ferrule has relatively thin walls and is made of a malleable metal material, such as low carbon steel. The end of the tube, which may be provided with short annular flanges or beads to provide a better connection with the interior of a hose, is inserted through the circular aperture and into the body of the sleeve ferrule. Cold forming equipment is then used to create an annular bead directly to either side of the closed end ferrule wall, thereby locking the ferrule onto the tube. In other designs, a preformed single bead or shoulder may be utilized to retain a suitable fitting or ferrule, typically a pair of interlocking threaded members used in conjunction with an O-ring. A hose may then be inserted into the open end of the sleeve ferrule and onto the end of the tube, and the annular sleeve is then crimped to lock the hose, ferrule and tube together. If the hose fails, as often occurs in high pressure applications, the hose and ferrule can be cut away from the tube, but since the annular bead locks or shoulders are already in place on the tube, the hose cannot be replaced using the normal manufacturing process. This means that such hose and tube combinations cannot be repaired in the field but must be replaced with factory manufactured equipment.
It is an object of this invention to provide a means and method for repairing hose and tube combinations originally joined by a bead lock type fitting, which enables a replacement hose to be connected onto the original tube having the annular bead, shoulder or bead pair. This object is accomplished, as set forth in greater detail below, by providing a new construction for a sleeve ferrule, the new ferrule having a tubular extension joined to the closed end of the ferrule, the tubular extension being sized to fit over the annular beads and formed of a malleable material which allows the extension to be radially compressed onto the tube beyond the annular beads to affix the ferrule to the tube, thereby allowing a hose to be inserted into the ferrule and over the tube end, with the ferrule then crimped to the hose in normal manner.